Freedom is a word whose meaning changes depending on the context. In the musical sense, 'free' is applied to an open-ended kind of improvised jazz, where musicians play without foreknowledge, without the safety-net of strict time or pre-set chord changes. In the political sense, it means a state of liberty, where the citizen is unbound by rules. A few potent pop songs from the sixties evoke that sense of living without limits which is the promise of freedom. I might mention 'Georgy Girl' by the Seekers, 'Ticket to Ride' by the Beatles and 'Summer Holiday' by Cliff Richard.

Spaceheads, the duo comprised of Andy Diagram and Richard Harrison, are very much part of the international free jazz community, yet their stuff is very structured, bound by the technology of loops and harmonisers and effects that transforms Diagram's single trumpet into a complete orchestra. And Harrison is the funkiest of all improvising drummers, as much Pretty Purdie as Andrew Cyrille. Sun Radar, the title-track of this 4-track EP, is Bonkers Blaxploitation with gurgling electronica taking the role of wah-wah guitar. The funk of 'Atomic Clock' is urgent and implacable with a touch of dread. So far, so Spaceheads.

But I was really hooked by 'Miles to Go', where Harrison's hammering tirade is allied to a melody that could be Neal Hefti or Burt Bacharach. In other words, a throwback to the limitless promise of the sixties, as in definition three above. The fourth cut 'North of the Border' uses drifting chords and echoing beats to set up a sense of expectation, which it then realises with a tune of, well, words are inadequate to describe… Ninja triumphalism? (It sounds vaguely oriental anyway.) In short, it's fab!

I love the playfulness of Spaceheads, the way they integrate pop culture into their artful constructions (lots of wide-screen cinema on this one) and the way the transcend the clatter and clutter with the direct simplicity of melody. I love them for the unabashed sense of pleasure they communicate. Their longevity (Diagram has quit and rejoined James a few times during their lifespan) means that the technology they use has passed from novelty to common currency. It doesn't matter; it's what they do with it. Spaceheads, a small and flexible unit, delineate the possibilities of trumpet, percussion and electronica with an endless, inexhaustible imagination.

And could the title, Sun Radar be a nod to the gentle genius of avant-garde jazz? Almost certainly. The EP comes in vinyl and CD format; I would plump for the 180 gram sonic majesty of the former.